Ok fill me in here but IMO rear is a complete waste of time? If you're getting pinged from behind with radar and you're still going too fast then you are a big stupidhead and should receive a ticket? If you get pinged from behind with laser and you're going too fast you're getting a ticket anyway. But I have literally never seen an enforcement situation where they were clocking cars from behind.

High up for front radar is definitely better, I just lost most of the rear laser detection on mine when above the rear mirror. I high mount in rural areas and just below mirror for expressways. The laser on overpasses are just too common.   Still I have an old set of jammers in storage that i just realised I could convert to detect only and fit.

No metrics to go off, but general consensus from what I've been reading is the higher the better in general, anything to get them clear of internal obstructions ie seats/headrests etc as well as improving sightlines over other cars/hill crests as well🤷‍♂️   I've had plenty of rear alerts for what its worth, but still getting to grips with all the settings/understanding all the things that set them off/adjustments to reduce false alarms

How’s the rear detection with it mounted so high up? 

Since I've been enjoying my car too much lately....radar detector install time! Its on one of those nice quick release powered mounts, NZ crowd I think? https://www.readysetradars.com/products/uniden-r7-8-mount   It works well, nice and solid over bumps and corners even with coilovers, so can recommend. install was easy...was hoping to power from cabin lights but no switched 12v there...so ran cable down to stereo and tapped into switched power for ciggy lighter since it was easier than dealing with all the fleece taped stereo harness  and the supplied cable with mount is the peeerfect length. The audio lead I added to wire into DSP since it can do auto source switching so I can get alerts through the stereo system ie interrupt audio from headunit, havent set that up yet though.   They also do an angle correction kit for the stupid angled display which makes it face flat into the car with minimal effect on detection ability, out of stock at the moment but its just a couple of screws and replaces the metal tab the detector clips onto to, so I'll grab one when they show up next.